Individual test strips have previously been used in practice for the self-diagnosis of diabetics and are examined electrochemically or photometrically after the application of a small amount of sample in order to determine the glucose content in a blood sample as exactly and reliably as possible. In this process the measuring strips are usually held during the measurement by holding structures which are parts of the housing of a hand-held device. This should ensure that the measuring field on the test strip is situated relatively accurately in relation to, for example in an optical system, the scanning optical measurement system because this is also attached to the housing components. The used individual strips are removed from the device after completion of the measurement and are disposed of By doing without disposal within the device, space is saved in a small hand-held device and the housing which has relatively large construction tolerances does not have to be involved in further primary system functions. In this connection it should be taken into consideration that the device housing usually has to fulfill several functions simultaneously: covering (protection of the system), design representation, positioning of the individual components relative to one another and mechanical stiffening. This shift of many functions into one component generates several contradictory requirements and has the effect that the implementation of the primary functionality (covering and design representation) is made more difficult while at the same time the other functional demands—mechanical stiffening and precise relative positioning of the system assembly units—are insufficiently achieved.
In order to achieve additional application advantages, it has already been proposed that a plurality of tests be provided and disposed of again on a test tape in the form of a tape cassette. Such tape cassettes are intended to be inserted as a disposable part into compact hand-held devices in order to allow all necessary analytical steps to be carried out automatically and rapidly.
On this basis the object of the invention is to further improve the test systems proposed in the prior art and achieve in a compact design a high positioning accuracy and particular user friendliness when using tape cassettes.